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Magnesium (Mg) homeostasis is critical for maintaining many biological processes, but little information is available to comprehend the molecular mechanisms regulating Mg concentration in rice (Oryza sativa). To make up for the lack of information, we aimed to identify mutants defective in Mg homeostasis through a forward genetic approach. As a result of the screening of 2,825 M2 seedlings mutated by ion-beam irradiation, we found a rice mutant that showed reduced Mg content in leaves and slightly increased Mg content in roots. Radiotracer 28Mg experiments showed that this mutant, named low-magnesium content 1 (LMGC1), has decreased Mg2+ influx in the root and Mg2+ translocation from root to shoot. Consequently, LMGC1 is sensitive to the low Mg condition and prone to develop chlorosis in the young mature leaf. The MutMap method identified a 7.4-kbp deletion in the LMGC1 genome leading to a loss of two genes. Genome editing using CRISPR-Cas9 further revealed that one of the two lost genes, a gene belonging to the RanBP2-type zinc-finger family that we named RanBP2-TYPE ZINC FINGER1 (OsRZF1), was the causal gene of the low Mg phenotype. OsRZF1 is a nuclear protein and may have a fundamental role in maintaining Mg homeostasis in rice plants.
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Oryza , Oryza/metabolismo , Magnésio/metabolismo , Raízes de Plantas/metabolismo , Plântula/genética , Mutação/genética , Zinco/metabolismoRESUMO
PURPOSE: To investigate the relationship between changes in pulmonary function (PF) and patient-reported outcomes (PROs) of lung cancer surgery. METHODS: We recruited 262 patients who underwent lung resection for lung cancer, to evaluate the PROs, using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ)-C30 and the Lung Cancer 13-question supplement (LC13). The patients underwent PF tests and PRO assessments preoperatively (Pre) and 1 year after surgery (Y1). Changes were calculated by subtracting the value at Pre from the value at Y1. We set two cohorts: patients under the ongoing protocol (Cohort 1) and patients who were eligible for lobectomy with clinical stage I lung cancer (Cohort 2). RESULTS: Cohorts 1 and 2 comprised 206 and 149 patients, respectively. In addition to dyspnea, changes in PF were also correlated with scores for global health status, physical and role function scores, fatigue, nausea and vomiting, pain, and financial difficulties. Absolute correlation coefficient values ranged from 0.149 to 0.311. Improvement of emotional and social function scores was independent of PF. Sublobar resection preserved PF more than lobectomy did. Wedge resection mitigated dyspnea in both cohorts. CONCLUSION: The correlation between PF and PROs was found to be weak; therefore, further studies are needed to improve the patient's postoperative experience.
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Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Qualidade de Vida , Pulmão , Medidas de Resultados Relatados pelo Paciente , Dispneia/etiologia , Inquéritos e QuestionáriosRESUMO
Magnesium is an important nutrient for plants, but much is still unknown about plant Mg2+ transporters. Combining with the structural prediction of AlphaFold2, we used mutagenesis and 28Mg uptake assay to study the highly conserved "GMN" motif of Arabidopsis thaliana MRS2-1 (AtMRS2-1) transporter. We demonstrated that the glycine and methionine in GMN motif are essential for AtMRS2-1 to transport Mg2+.
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Proteínas de Arabidopsis , Arabidopsis , Proteínas de Transporte de Cátions , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Transporte de Cátions/genética , Magnésio/metabolismo , MutagêneseRESUMO
PURPOSE: We demonstrate cyclotron production of high-quality 225Ac using an electroplated 226Ra target. METHODS: 226Ra was extracted from legacy Ra sources using a chelating resin. Subsequent ion-exchange purification gave pure 226Ra with a certain amount of carrier Ba. The radium target was prepared by electroplating. We successfully deposited about 37 MBq of 226Ra on a target box. Maximum activation was achieved using 15.6 MeV protons on the target at 20 µA for 5 h. Two functional resins with various concentrations of nitric acid purified 225Ac and recovered 226Ra. Cooling the intermediate 225Ac for 2-3 weeks decayed the major byproduct of 226Ac and increased the radionuclidic purity of 225Ac. Repeating the same separation protocol provided high-quality 225Ac. RESULTS: We obtained 225Ac at a yield of about 2.4 MBq at the end of bombardment (EOB), and the subsequent initial purification gave 1.7 MBq of 225Ac with 226Ac/225Ac ratio of < 3% at 4 days from EOB. Additional cooling time coupled with the separation procedure (secondary purification) effectively increased the 225Ac (4n + 1 series) radionuclidic purity up to 99 + %. The recovered 225Ac had a similar identification to commercially available 225Ac originating from a 229Th/225Ac generator. CONCLUSION: This procedure, which involves the 226Ra(p,2n)225Ac reaction and the appropriate purification, has the potential to be a major alternative pathway for 225Ac production because it can be performed in any facility with a compact cyclotron to address the increasing demand for 225Ac.
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Ciclotrons , Rádio (Elemento) , Humanos , Prótons , RadioisótoposRESUMO
An aberrant arterial aneurysm with pulmonary sequestration is rare. Here, we report about a 35-year-old man who had no symptoms related to pulmonary sequestration. Computed tomography revealed an aberrant arterial aneurysm with an 18 mm in diameter with intralobar pulmonary sequestration, which gradually increased in size to 27 mm over 5 years. The patient underwent thoracic endovascular aortic repair with coil embolization for the aneurysmal distal branches to prevent aneurysm rupture. The postoperative course was unremarkable without a need for lobectomy. During a 1-month follow-up period, the aneurysm shrunk with no endoleaks. Stent-graft placement and coil embolization represent an effective and less invasive treatment option to completely block systemic arterial flow and unexpected retrograde backflow and control the expansion of the aneurysm.
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Aorta Torácica/cirurgia , Aneurisma da Aorta Torácica/cirurgia , Implante de Prótese Vascular , Sequestro Broncopulmonar/complicações , Embolização Terapêutica , Procedimentos Endovasculares , Adulto , Aorta Torácica/anormalidades , Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/complicações , Aneurisma da Aorta Torácica/diagnóstico por imagem , Prótese Vascular , Implante de Prótese Vascular/instrumentação , Sequestro Broncopulmonar/diagnóstico por imagem , Procedimentos Endovasculares/instrumentação , Humanos , Masculino , Stents , Resultado do TratamentoRESUMO
The performance indicator called limit of detection for microarray platform (LODP) was defined in ISO 16578:2013. The methods to determine practical LODP were explored. In general, + 3 SD of the background is used as the signal strength of limit of detection and criteria for dividing positive and negative results. Since the negative signal had been defined differently for each microarray platform, signals obtained from Non-Probe Spots (NPS) installed on the microarrays were defined as the "background" of microarrays. LODP was determined as the lowest concentration of which the average signal exceeded Avg. + 3 SD of the background (NPS) and the signal was significantly different from those of the lower and higher adjacent concentration points measured with a diluted series of reference materials. For reliable qualitative analysis, the positive results can be defined as signals higher than those corresponding to LODP and negative results as lower signals, without determining limit of detection for all target probes. The use of LODP also enables comparisons of platform performances without checking sequence dependencies, and assists to select reliable and fitting platforms for experimental purposes.
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Perfilação da Expressão Gênica/métodos , Limite de Detecção , Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA/análise , Reprodutibilidade dos TestesRESUMO
MAIN CONCLUSION: The Mg2+ uptake system in Arabidopsis roots is Gd3+- and Fe2+-sensitive, and responds to a changing Mg2+ concentration within 1 h with the participation of AtMRS2 transporters. Magnesium (Mg2+) absorption and the mechanism regulating its activity have not been clarified yet. To address these issues, it is necessary to reveal the characteristics of Mg2+ uptake in roots. Therefore, we first investigated the Mg2+ uptake characteristics in roots of 1-week-old Arabidopsis plants using 28Mg. The Mg2+ uptake system in roots was up-regulated within 1 h in response to the low Mg2+ condition. This induction was inhibited in Arabidopsis "mitochondrial RNA splicing 2/magnesium transport" mutants atmrs2-4/atmgt6 and atmrs2-7/atmgt7, while the expression of AtMRS2-4/AtMGT6 and AtMRS2-7/AtMGT7 genes in the Arabidopsis wild-type was not responsive to Mg2+ conditions. In addition, the Mg deficiency-induced Mg2+ uptake system was shut-down within 5 min when Mg2+ was resupplied to the environment. An inhibition study showed that the constitutive mechanism functioning in Mg2+ uptake under Mg2+ sufficient conditions was sensitive to a number of divalent and trivalent cations, particularly Gd3+ and Fe2+, but not to K+.
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Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Magnésio/metabolismo , Transporte Biológico , Isótopos/análise , Raízes de Plantas/metabolismo , Estresse FisiológicoRESUMO
Although wandering is a common behavioral problem in patients with dementia, information about wandering in patients with severe dementia is scarce. This study analyzed data about the wandering behavior of a 77-year-old woman with severe frontotemporal dementia. Due to severe atrophy of the anterior cortex, she was totally unable to act spontaneously. Nevertheless, she walked with her husband every day. Her walking pattern varied on a daily basis but it appeared to be random. However, a mathematical analysis showed that her walking pattern was not random. Our case suggests that even patients with severe atrophy in the anterior cortex may be able to orient themselves within their neighborhood if their posterior cortex is preserved.
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Demência Frontotemporal/fisiopatologia , Demência Frontotemporal/psicologia , Comportamento Errante/fisiologia , Idoso , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Feminino , Demência Frontotemporal/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Comportamento Espacial/fisiologia , Tomografia Computadorizada de Emissão de Fóton Único , CaminhadaRESUMO
To maintain sterility of PET drug is the most important for in-house positron emission tomography (PET) drug manufacturing, and sanitary control of the laboratory to perform aseptic procedure is the key point for the sterility of PET drugs. However, rigorous sanitary control affects both the high cost and the low efficiency. To conquer those, we developed an isolator system especially for PET drug compounding including sterilization and dispensing units. This system consists of a HEPA unit for inlet and outlet, positive regulation of the ear inside isolator, a sterilizer with vapored hydrogen peroxide and a dispenser with self-shield for radiation. We set the materials for the dispenser through gloves, and the compounding such as sterilization and dispensing PET drugs to the containers is performed automatically without radiation. High level assurance of PET drug sterility is expected to be accomplished in the PET centers of the hospitals without high level sanitary control.
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BACKGROUND: Hyponatremia is the most common electrolyte disorder and is a negative prognostic factor in several kinds of cancer. However, few reports have referred to hyponatremia in non-small cell lung cancer (NSCLC). In the present study, the authors examined the influence of preoperative serum sodium concentration on survival in completely resected NSCLC. METHODS: A total of 386 completely resected NSCLC patients were retrospectively analyzed. RESULTS: Kaplan-Meier survival curves showed that serum sodium concentration was a significant prognostic factor, and the log-rank statistical value was maximum (9.173, p = 0.002) when the cutoff value of serum sodium concentration was 139 mEq/L. The overall 5-year survival rate of the high-serum sodium concentration group (> 139 mEq/L) was 74.8% and that of the low-serum sodium concentration group (≤ 139 mEq/L) was 59.7%. Clinicopathological factors showed significant differences between the two groups for leukocyte count, neutrophil count, C-reactive protein, tumor size, and pleural invasion. CONCLUSIONS: Low-serum sodium concentration, which was associated with tumor status and inflammation, had negative prognostic influence in completely resected NSCLC.
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Carcinoma Pulmonar de Células não Pequenas/cirurgia , Hiponatremia/complicações , Neoplasias Pulmonares/cirurgia , Pneumonectomia , Sódio/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Carcinoma Pulmonar de Células não Pequenas/complicações , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Distribuição de Qui-Quadrado , Feminino , Humanos , Hiponatremia/sangue , Hiponatremia/diagnóstico , Hiponatremia/mortalidade , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Pneumonectomia/efeitos adversos , Pneumonectomia/mortalidade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Pulmonary artery sarcomas (PASs) are rare, and complete tumor resection is often difficult at the time of detection. We encountered a case of PAS that was thought to be resectable; however, the patient had severe symptomatic valvular disease. We faced a difficult decision regarding the surgical strategy. CASE PRESENTATION: A 76-year-old female presented with a history of polysurgery for multiple primary cancers. She was referred to our department with a calcified mass in the right pulmonary artery (PA) and severe symptomatic valvular disease. After a discussion with the cardiovascular surgeon, we decided to perform a two-stage surgery. She underwent valvuloplasty through a median sternotomy, resulting in an improvement in her exertional dyspnea. The tumor was removed three months later with a right upper lobectomy and PA patch reconstruction through a posterolateral thoracotomy. When the PA was opened, the edge of the tumor was entrapped by vascular clamp forceps because of insufficient dissection of the adhesions between the superior vena cava and the right main PA resulting from the first operation. The patient underwent proton therapy twice for chest wall metastases which recurred three months after surgery, and local recurrence in the PA was diagnosed five months after surgery. The patient was alive with stable disease 25 months after surgery. CONCLUSION: Two-stage surgery for PAS and valvular disease resulted in incomplete resection of the PAS in the right PA. It is important not to underestimate surgical adhesions due to the initial surgery and to consider and implement measures to prevent adhesions of critical vessels during the second operation.
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Copper (Cu) is a critical element for cancer cell proliferation and considerably accumulates in the nucleus. 64Cu2+ is an anticancer radiopharmaceutical that targets the copper requirement of cancer cells. However, intravenously injected 64Cu2+ ions primarily accumulate in the liver. Ligand complexation of 64Cu2+ may be a promising method for increasing tumor delivery by reducing liver uptake. In this study, we used three tripodal amine ligands [tris(2-aminoethyl)amine (Tren), diethylenetriamine (Dien), and tris(2-pyridylmethyl)amine (TPMA)] to enclose 64Cu2+ ions and compared their in vivo tumor and liver uptakes using a tumor-bearing xenograft mouse model of the extrahepatic bile duct carcinoma cell line TFK-1. We examined intracellular Cu distribution using microparticle-induced X-ray emission (micro-PIXE) analysis of these compounds. 64Cu2+-Tren and 64Cu2+-Dien showed higher tumor uptake than 64Cu2+-TPMA and 64Cu2+ ions in TFK-1 tumors. Among the three 64Cu2+ complexes and 64Cu2+ ions, liver uptake was inversely correlated with tumor uptake. Micro-PIXE analysis showed that in vitro cellular uptake was similar to in vivo tumor uptake, and nuclear delivery was the highest for 64Cu2+-Tren. Conclusively, an inverse correlation between tumor and liver uptake was observed using three 64Cu2+ complexes of tripodal amine ligands and 64Cu2+ ions. These results provide useful information for the future development of anticancer 64Cu radiopharmaceuticals.
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Maintenance of an appropriate magnesium ion (Mg(2+)) concentration is essential for plant growth. In Arabidopsis thaliana, the CorA-MRS2-ALR-type proteins, named MRS2/MGT family proteins, are reportedly localized in various membranes and they function in Mg transport. However, knowledge of this family in other plant species is extremely limited. Furthermore, differential diversification among dicot and monocot plants suggested by phylogenetic analysis indicates that the role of the Arabidopsis MRS2/MGT family proteins is not the same in monocot plants. For a further understanding of this family in higher plants, functional analysis and gene expression profiling of rice MRS2/MGT family members were performed. A phylogenetic tree based on the isolated mRNA sequences of nine members of the OsMRS2 family confirmed that the MRS2/MGT family consists of five clades (A-E). A complementation assay in the yeast CM66 strain showed that four of the nine members possessed the Mg(2+) transport ability. Transient green fluorescent protein (GFP) expression in the isolated rice protoplast indicated that OsMRS2-5 and OsMRS2-6, belonging to clades D and A, respectively, localized in the chloroplast. Expression levels of these genes were low in the unexpanded yellow-green leaf, but increased considerably with leaf maturation. In addition, diurnal oscillation of expression was observed, particularly in OsMRS2-6 expression in the expanded leaf blade. We conclude that OsMRS2 family members function as Mg transporters and suggest that the genes belonging to clade A encode the chloroplast-localized Mg(2+) transporter in plants.
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Proteínas de Transporte de Cátions/genética , Regulação da Expressão Gênica de Plantas , Magnésio/metabolismo , Oryza/genética , Proteínas de Plantas/genética , Sequência de Aminoácidos , Sequência de Bases , Proteínas de Transporte de Cátions/classificação , Proteínas de Transporte de Cátions/metabolismo , Cloroplastos/metabolismo , Teste de Complementação Genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Microscopia Confocal , Dados de Sequência Molecular , Família Multigênica , Mutação , Oryza/metabolismo , Filogenia , Proteínas de Plantas/classificação , Proteínas de Plantas/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Protoplastos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , Homologia de Sequência de Aminoácidos , Fatores de TempoRESUMO
Background: An optimal surgical procedure for primary spontaneous pneumothorax (PSP) has not yet been established. The study aimed to compare patient-reported outcomes (PROs) and clinical outcomes between parietal pleurectomy (pleurectomy) and visceral pleural covering with absorbable prosthesis (covering) added to thoracoscopic bullectomy in patients with PSP. Methods: From January 2015 to April 2018, PROs were prospectively evaluated using EuroQOL-5 dimensions-5 levels (EQ5D). Questionnaires were administered preoperatively and at 1, 3, and 5 days and 1 month postoperatively. The perioperative outcomes were compared retrospectively. Recurrences and postoperative symptoms in the distant period were investigated cross-sectionally by telephone and mail surveys in February 2020. Results: In total, 26 and 29 patients underwent covering and pleurectomy, respectively. The visual analog scale score of the EQ5D on postoperative day 1 was significantly better in the pleurectomy group than in the covering group. There was no significant difference in the frequency of PROs in the EQ5D including pain. Perioperative outcomes, such as postoperative chest tube placement, and hospital stay, were comparable between the groups, except for the operative time. There was no significant difference in the recurrence rate and frequency of residual symptoms, e.g., chest discomfort in the long-term outcomes. Conclusions: PROs and clinical outcomes were comparable between the two procedures. Further studies are required to determine the optimal treatment procedure.
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[64Cu]Cu-diacetyl-bis(N4-methylthiosemicarbazone) ([64Cu]Cu-ATSM) is a radioactive hypoxia-targeting therapeutic agent being investigated in clinical trials for malignant brain tumors. For the quality management of [64Cu]Cu-ATSM, understanding trace metal impurities' effects on the chelate formation of 64Cu and ATSM is important. In this study, we conducted coordination chemistry studies on metal-ATSM complexes. First, the effects of nonradioactive metal ions (Cu2+, Ni2+, Zn2+, and Fe2+) on the formation of [64Cu]Cu-ATSM were evaluated. When the amount of Cu2+ or Ni2+ added was 1.2 mol or 288 mol, equivalent to ATSM, the labeling yield of [64Cu]Cu-ATSM fell below 90%. Little effect was observed even when excess amounts of Zn2+ or Fe2+ were added to the ATSM. Second, these metals were reacted with ATSM, and chelate formation was measured using ultraviolet-visible (UV-Vis) absorption spectra. UV-Vis spectra showed a rapid formation of Cu2+ and the ATSM complex upon mixing. The rate of chelate formation by Ni2+ and ATSM was lower than that by Cu-ATSM. Zn2+ and Fe2+ showed much slower reactions with the ATSM than Ni2+. Trace amounts of Ni2+, Zn2+, and Fe2+ showed little effect on [64Cu]Cu-ATSM' quality, while the concentration of impurity Cu2+ must be controlled. These results can provide process management tools for radiopharmaceuticals.
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INTRODUCTION AND IMPORTANCE: Thrombosis in the pulmonary vein stump (PVS) after lung resection has been reported as a cause of cerebral infarction (CI). However, there is limited research focusing on thrombosis in the PVS. Although anticoagulant therapy is performed in clinical settings, the optimal duration of anticoagulant therapy is not established. In addition, no case leading to CI after withdrawal of the anticoagulant therapy has been reported. CASE PRESENTATION: An 81-year-old woman with lung cancer underwent left lower lobectomy. Since a thrombus was detected in the PVS 6 months after the operation, anticoagulant therapy was started. The thrombus disappeared 1 month later, and the medication was discontinued. However, only 23 days after discontinuation, the patient developed CI. CLINICAL DISCUSSION: This case was considered as cardiogenic CI due to a thrombus in the PVS because of the presence of the past thrombus, the distribution of infarction, and the absence of atrial fibrillation. The length of PVS in this case was longer than that reported previously, which could have caused turbulence and congestion leading to thrombogenesis. As long as patients have a long neck PVS, there might be a potential risk of thrombosis. CONCLUSION: We must recognize the risks associated with the discontinuation of anticoagulant therapy for thrombosis in PVS even after thrombus dissipation.
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Oil-in-water (O/W) emulsions containing ethanol have been used in food, cosmetics, paints, and other applications. However, O/W emulsions with long-term stability are difficult to produce at high ethanol concentrations because the adsorption of the emulsifier at the O/W interface is restricted by ethanol. In this study, to resolve this issue, we prepared ethanol-containing O/W emulsions with high dispersion stability using a series of polyglycerol monofatty acid esters (PGFEs) with different fatty acid chain lengths, which are bio-safe nonionic surfactants, as emulsifiers. First, aqueous PGFE solutions containing 0-50 wt% ethanol were prepared and then O/W emulsions were formed using limonene as the oil phase. When decaglycerol stearic acid ester (DGMS, C18) was used as the emulsifier, an O/W emulsion with fine droplets (~30 nm in size) was successfully obtained at an ethanol concentration of 35 wt%. This emulsion remained stable for more than four weeks, during which no phase separation occurred, indicating its high dispersion stability. Furthermore, aqueous DGMS solutions containing 30-40 wt% ethanol were viscous, and a lamellar liquid crystal phase was observed to be dispersed in these solutions. The formation of this lamellar liquid crystal phase at the O/W interface led to an interfacial film with superior viscoelastic properties. The results suggested that the stability of the emulsions was determined by the balance between the decrease in interfacial tension caused by the addition of ethanol and the density (rigidity) of the DGMS film formed at the O/W interface. Finally, to further improve the dispersion stability of the ethanol-containing O/W-type emulsions, O/W emulsions were prepared using a mixture of two PGFEs with different degrees of glycerol polymerization, that is, systems having different hydrophilic-lipophilic balance values.
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Ésteres , Glicerol , Emulsificantes/química , Emulsões/química , Ésteres/química , Etanol , Glicerol/química , Polímeros , Água/químicaRESUMO
CD133 has been recognized as a prominent biomarker for cancer stem cells (CSCs), which promote tumor relapse and metastasis. Here, we developed a clinically relevant, stable, and peptide-based positron emission tomography (PET) tracer, [64Cu]CM-2, for mapping CD133 protein in several kinds of cancers. Through the incorporation of a 6-aminohexanoic acid (Ahx) into the N terminus of a CM peptide, we constructed a stable peptide tracer [64Cu]CM-2, which exhibited specific binding to CD133-positive CSCs in multiple preclinical tumor models. Both PET imaging and ex vivo biodistribution verified the superb performance of [64Cu]CM-2. Furthermore, the matched physical and biological half-life of [64Cu]CM-2 makes it a state-of-the-art PET tracer for CD133. Therefore, [64Cu]CM-2 PET may not only enable the longitudinal tracking of CD133 dynamics in the cancer stem cell niche but also provide a powerful and noninvasive imaging tool to track down CSCs in refractory cancers.
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Peptides that are composed of dextrorotary (d)-amino acids have gained increasing attention as a potential therapeutic class. However, our understanding of the in vivo fate of d-peptides is limited. This highlights the need for whole-body, quantitative tracking of d-peptides to better understand how they interact with the living body. Here, we used mouse models to track the movement of a programmed death-ligand 1 (PD-L1)-targeting d-dodecapeptide antagonist (DPA) using positron emission tomography (PET). More specifically, we profiled the metabolic routes of [64Cu]DPA and investigated the tumor engagement of [64Cu/68Ga]DPA in mouse models. Our results revealed that intact [64Cu/68Ga]DPA was primarily eliminated by the kidneys and had a notable accumulation in tumors. Moreover, a single dose of [64Cu]DPA effectively delayed tumor growth and improved the survival of mice. Collectively, these results not only deepen our knowledge of the in vivo fate of d-peptides, but also underscore the utility of d-peptides as radiopharmaceuticals.
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Organic solute carrier partner 1 (OSCP1) is a mammalian, transporter-related protein that is able to facilitate the uptake of structurally diverse organic compounds into the cell when expressed in Xenopus laevis oocytes. This protein has been implicated in testicular handling of organic solutes because its mRNA expression is almost exclusive in the testis. However, in this study, we demonstrated significant expression of OSCP1 protein in mouse brain, the level of which was rather higher than that in the testis, although the corresponding mRNA expression was one-tenth of the testicular level. Immunohistochemistry revealed that OSCP1 was broadly distributed throughout the brain, and various neuronal cells were immunostained, including pyramidal cells in the cerebral cortex and hippocampus. However, there was no evidence of OSCP1 expression in glia. In primary cultures of cerebral cortical neurons, double-labeling immunofluorescence localized OSCP1 to the cytosol throughout the cell body and neurites including peri-synaptic regions. This was consistent with the subcellular fractionation of brain homogenates, in which OSCP1 was mainly recovered after centrifugation both in the cytosolic fraction and the particulate fraction containing synaptosomes. Immunoelectron microscopy of brain sections also demonstrated OSCP1 in the cytosol near synapses. In addition, it was revealed that changes in the expression level of OSCP1 correlated with neuronal maturation during postnatal development of mouse brain. These results indicate that OSCP1 may have a role in the brain indirectly mediating substrate uptake into the neurons in adult animals.